Methods and Apparatus for Identification of Container Contents Based on Radio Frequency Identification Technology

ABSTRACT

A method includes acquiring, via an antenna disposed within a container, information associated with a radio frequency identification tag coupled to an object disposed within a container via an antenna. The information is transferred to an exterior radio frequency identification tag disposed outside of the container. The exterior radio frequency identification tag is configured to send an inventory indicator associated with the information to an external interrogator unless the container is open.

CROSS REFERENCE TO RELATED APPLICATION

This application is a Continuation of U.S. patent application Ser. No.10/707,511, filed Dec. 18, 2003, now U.S. Pat. No. 7,256,682, theentirety of which is hereby incorporated by reference.

BACKGROUND

This invention relates to a method and apparatus for performing theremote, real-time identification of the contents of containers by meansof multiple radio frequency identification systems.

Radio Frequency ID (RFID) systems allow for the identification ofobjects at a distance and out of line of sight. They are comprised oftransponders called radio frequency (RF) tags and RF interrogators (alsocalled readers). The tags are smaller, sometimes as small as a grain ofrice, less expensive than interrogators, and are commonly attached toobjects such as product packages in stores. When an interrogator comeswithin range of an RF tag, it may provide power to the tag via aquerying signal, or the RF tag may use stored power from a battery orcapacitor to send a radio frequency signal to be read by the RFIDinterrogator.

RF tags may consist of single integrated circuits, circuits andantennae, or may incorporate more complex capabilities such ascomputation, data storage, and sensing means. Some categories of RFIDtags include the following: passive tags that acquire power via theelectromagnetic field emitted by the interrogator, semi-passive tagsthat respond similarly, but also use on-board stored power for otherfunctions, active tags that use their own stored power to respond to aninterrogator's signal, inductively coupled tags that operate at lowfrequencies and short distances via a coil antenna, single or dipoleantenna-equipped tags that operate at higher frequencies and longerdistances, read-write tags that can alter data stored upon them,full-duplex or half duplex tags, collision arbitration tags that may beread in groups, or non-collision tags that must be read individually.

RFID systems present a number of advantages over other object markingand tracking systems. A radio frequency interrogator may be able to reada tag when it is not in line of sight from the interrogator, when thetag is dirty, or when a container obscures the tag. RFID systems mayidentify objects at greater distances than optical systems, may storeinformation into read/write tags, do not require a human operator, andmay read tags hidden from visual inspection for security purposes. Theseadvantages make RFID systems useful for tracking objects.

Generally, less expensive RFID systems have lesser capabilities. Forinstance, passive tags may have very low cost per unit, facilitatingwidespread use, but they also have limited range. RFID systems may alsofail when applied to groups of objects, containers of multiple objects,or nested containers of objects. For shipping and warehousing of largecontainers on pallets, which often contain nested containers,inexpensive passive tags on individual objects may not provide adequateidentification rates. Human manipulation of such objects may affordacceptable identification rates, but it also increases the cost ofidentifying each object. Active tags have greater range, but they may beimpractical in many instances because of cost, shelf life, RFinterference or other reasons. There is a need for a system that allowsfor the use of multiple tag types for groups of objects in potentiallymobile containers that delivers a high read rate under a variety ofconditions, at a distance, and at a reasonable cost. Such a systempresents an advantage over prior art by surmounting compatibility issuespresented by environments equipped with RFID systems of one type thatneed to process items tagged by a system of a different type.

U.S. Pat. No. 6,127,928 discloses an apparatus and method for a radiofrequency document control system that enables the location ofdocuments, such as office files, to be automatically and rapidlyidentified. The apparatus differs from this invention in a number ofregards: the intermediate transceiver is not attached to a mobilecontainer or described as operating while in motion; it requires apersonal computer or other computation means to process the identity ofdocuments; and its order of communication between transceivers does notallow for switched, efficient scanning of a container's content.

U.S. Pat. No. 6,529,446 discloses an interactive medication container orconsole that holds or otherwise organizes one or more medication vialsor containers. The system automatically acquires information from memorystrips on the vials or containers that is then made available to anexternal data processing system. It differs from this invention inseveral important regards: the medication container does not communicatevia RFID with the external world, and the invention does not facilitatethe rapid remote inventory of a mobile container.

U.S. Pat. Application No. 2002/0183882 A1 discloses a point of sale anddelivery method and system using communication with remote computer andhaving features to read a large number of tags. The system resemblesthat disclosed in U.S. Pat. No. 6,529,446. It automatically acquiresinformation from tags on the products within a container and thenpresents them to an external data processing system. It differs fromthis invention in several important regards: the external container doesnot communicate its contents via RFID with the external world. Instead,it uses, in one embodiment, an external RFID system to restrict accessto the container. The invention does not provide the advantage oftranslating between incompatible RFID systems. The invention does notprovide the advantage of effective remote inventory of clustered ornested containers via an external RFID system.

SUMMARY

This invention relates to a method and apparatus for enabling theremote, real-time identification of the contents of containers by meansof multiple radio frequency identification (RFID) systems.

One embodiment of the apparatus comprises a container, an on-boardinterrogator with a mobile stored power means, a mechanical electricalswitch affixed to the container opening, an externally accessible radiofrequency (RF) tag, multiple tags affixed to objects sufficiently smallto lie within the container, and an external interrogator orinterrogators which communicate with the apparatus's externallyaccessible RF tag.

When the container is closed, the mechanical switch, which is affixed toits opening, signals to the on-board interrogator that it shouldfunction for a preset period of time. The interrogator then queries RFtags within its interior and reads their IDS into stored memory withinthe externally accessible RF tag attached to the container. When theexternal interrogator polls the externally accessible RF tag or detectsthe externally accessible RF tag's beacon, it acquires the inventory ofthe internal tags that was established at the time the container wasclosed. Because the externally accessible RF tag may be an active tagwith significant stored power, a potentially more effective frequency,and with less shielding by the container walls, it may have a muchgreater range and capacity to surmount obstacles than the RF tags withinthe container. The structure of the container, externally accessible RFtag, and antenna may be configured such that a desired successful readrate can be achieved given known configurations of containers. Theapparatus allows for automatic translation between RFID systems: whilethe container's interior may be populated with RF tags that cannot byread by an external interrogator, as long as the externally accessibleRF tag is compatible, the entire group represented by the container andits contents may be inventoried by the external interrogator.

Another embodiment of the apparatus comprises a small mobile containersuch as an attache case, RFID tags, onboard interrogator, and a remoteRFID interrogator. Another embodiment comprises a large mobile containersuch as a cargo container or vehicle or trailer, RFID tags, on-boardinterrogator, and a remote RFID interrogator. Another embodimentcomprises a kit of components that may be used to retrofit existingcontainers of various sizes to give them the desired identificationcapabilities. Many embodiments of the invention are suitable for nesteduse.

The foregoing general description and the following detailed descriptionare exemplary and explanatory only and do not restrict the claimsdirected to the invention. The accompanying drawings, which areincorporated in and constitute a part of this specification, illustratesome embodiments of the invention and together with the description,serve to explain the principles of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagram illustrating an embodiment incorporated in anattache case.

FIG. 2 is a diagram illustrating an embodiment incorporated in a largecontainer.

FIG. 3 is a flowchart illustrating an operating cycle typical ofinventorying the container.

FIG. 4 is a flowchart illustrating an operating cycle typical ofremotely acquiring the inventory of the container.

DETAILED DESCRIPTION

The following detailed description of embodiments of this invention andthe attached figures are intended to provide a clear description of theinvention without limiting its scope.

FIG. 1 is a diagram illustrating an embodiment of the invention,incorporated in an attache case. The RF tag 101 is attached to an objector objects within the attache case. In this embodiment, the RF tag 101is a passive tag operating at 125 kHz, 13.56 MHz, or 900 MHz. The shapeof the objects within the attache, the shape of the attache, and theorientations of the RF tags with respect to the objects and theinterrogator/interrogator antenna 103 ensure that the rate of successfulread operations performed by the interrogator upon the interior objectsis optimal. In an alternate embodiment, compartments or dividers ormultiple interrogators might perform the same function for containersand objects of different geometries. Externally accessible RF tag 102 isan active or semi-passive tag that contains an inventory of the tagscontained within the attache as the identification code that it passesto external interrogators, either by beacon or in response to a pollingsignal from an interrogator. The externally accessible RF tag 102 mayalso be made to respond to activation of a physical switch or at presettime intervals or for a period after a triggering event. Tab 104 toggleselectrical switch 105 when the attache is opened or when the attache isclosed. Switch 105 initiates interrogation by interrogator/interrogatorantenna 103, powered by stored power means 106, comprising an electricbattery, fuel cell, or other stored power means. Data storage means andoptional data processing means may reside in 103 or 106. The componentsother than the container may collectively represent a kit that can beadded to an ordinary container to give it the advantages presented bythis invention.

FIG. 2 is a diagram illustrating an embodiment incorporated in a largecontainer. The RF tag 201 is attached to an object or objects within thecontainer 204. In this embodiment, the RF tag 201 is a passive tagoperating at 125 kHz, 13.56 MHz, or 900 MHz. Externally accessible RFtag 202 is an active or semi-passive tag that contains an inventory ofthe tags contained within the container as the identification code thatit passes to external interrogators, either by beacon or in response toa polling signal from an interrogator. The externally accessible RF tag202 may also be made to respond to activation of a physical switch or atpreset time intervals or for a period after a triggering event. When thecontainer door opens or when a motion sensor is tripped, electricalswitch 205 is toggled. Switch 205 initiates interrogation by either ofthe two interrogator/interrogator antenna 203, powered by stored powermeans 206, comprising an electric battery, fuel cell, or other storedpower means or by optional externally supplied power. Data storage meansand optional data processing means may reside in 202. The componentsother than the container may collectively represent a kit that can beadded to an ordinary container to give it the advantages presented bythis invention.

FIG. 3 is a flowchart illustrating an operating cycle typical ofinventorying the container. In 301, the cycle is initiated, generallywhen the apparatus is powered on or the stored power means is rechargedor refueled. In 302, the apparatus is in a power conserving state,waiting for the container door switch to toggle it into inventoryacquiring mode. In other embodiments a motion sensor or timer circuitmight trigger the acquisition of inventory. In 303, once the apparatushas entered inventory acquiring mode, it polls the RF tags attached tointernal objects, reads the RF tags' response signals, and stores theidentification values into the on-board memory means, such as EEPROMmemory. In 304, the apparatus checks to see if additional tags areavailable within the container for reading. If so, control returns to303. If not, then control proceeds to 305, where a test is made forwhether the interrogation period time interval has elapsed. If not, thencontrol is returned to 303. If so, then the apparatus ends internalinterrogator polling, returning to power conserving mode and ending theinventorying cycle.

FIG. 4 is a flowchart illustrating an operating cycle typical ofremotely acquiring the inventory of the container. The cycle begins in401, generally after the inventorying cycle of FIG. 3. In 402, eitherthe externally accessible RF tag sends a beacon at preset intervals orwaits for a signal from an external interrogator, depending on the RFtag type or mode of operation. In 403, once a polling signal has beendetected, the apparatus performs a test to determine whether thecontainer door is open. In 404, control returns to 403 if the door isopen to prevent transmission of erroneous inventory information. If thecontainer door is closed, control proceeds to 405, whereupon theapparatus sends the inventory of the container's contents to theexternal interrogator.

1. An apparatus, comprising: an antenna configured to be disposed withinan interior portion of a container and configured to receive aninventory-related information associated with an object disposed withinthe container; and a radio frequency identification tag configured to becoupled to an exterior portion of the container and configured toreceive the inventory-related information received at the antenna inresponse to the container being closed.
 2. The apparatus of claim 1,further comprising: a radio frequency identification tag configured tobe coupled to the interior portion of the container and configured to becoupled to the antenna, the radio frequency identification tagconfigured to be coupled to the interior portion of the container beingconfigured to acquire the inventory-related information via the antennain response to the container being closed.
 3. The apparatus of claim 1,wherein the inventory-related information is associated with a radiofrequency identification tag configured to be coupled to the object. 4.The apparatus of claim 1, wherein the inventory-related information isassociated with a radio frequency identification tag configured to becoupled to the object, at least one of the radio frequencyidentification tag configured to be coupled to the object or the objecthas a specified orientation relative to the antenna.
 5. The apparatus ofclaim 1, further comprising: a data storage component configured tostore the inventory-related information, the radio frequencyidentification tag configured to receive the inventory-relatedinformation from the data storage component.
 6. The apparatus of claim1, further comprising: a radio frequency identification interrogatorconfigured to be coupled to the interior portion of the container andincluding the antenna, the radio frequency identification interrogatorconfigured to be in communication with the radio frequencyidentification tag.
 7. The apparatus of claim 1, wherein the radiofrequency identification tag is configured to change from apower-conserving mode to an inventory-acquiring mode when a switchconfigured to be coupled to the container is toggled in response to thecontainer being closed.
 8. The apparatus of claim 1, wherein the radiofrequency identification tag is configured to translate theinventory-related information from a signal that is incompatible with anexternal radio frequency identification interrogator into a signal thatis compatible with the external radio frequency identificationinterrogator.
 9. The apparatus of claim 1, wherein the antenna isconfigured to receive the inventory-related information in response toat least one of a signal from a motion sensor or a signal produced by atimer.
 10. The apparatus of claim 1, wherein the radio frequencyidentification tag is configured to send an indicator of theinventory-related information to an external radio frequencyidentification interrogator within a specified time period of a requestfrom the external radio frequency interrogator.
 11. A method,comprising: acquiring, via an antenna disposed within a container,information associated with a radio frequency identification tag coupledto an object disposed within a container; and transferring theinformation to an exterior radio frequency identification tag disposedoutside of the container, the exterior radio frequency identificationtag configured to send an inventory indicator associated with theinformation to an external interrogator unless the container is open.12. The method of claim 11, wherein the antenna is configured to becoupled to a radio frequency interrogator disposed within the containerand in communication with the exterior radio frequency identificationtag.
 13. The method of claim 11, wherein the acquiring includesacquiring during an interrogation time period starting when thecontainer changes from being open to closed.
 14. The method of claim 11,wherein the container is a first container disposed within a secondcontainer, the antenna is a first antenna, the exterior radio frequencyidentification tag is a first exterior radio frequency identificationtag disposed within the second container, the method further comprising:acquiring information associated with the first exterior radio frequencyidentification tag via a second antenna disposed within the secondcontainer and configured to be disposed exterior to the first container;and transferring the information associated with the first exteriorradio frequency identification tag to a second exterior radio frequencyidentification tag disposed outside of the second container via thesecond antenna.
 15. The method of claim 11, wherein the acquiringincludes acquiring at a first time, the method further comprising:sending the information at a second time to the external interrogator asa beacon signal after a preset time interval has elapsed, the sendingbeing prevented when the container is open, the second time being afterthe first time.
 16. The method of claim 11, further comprising:receiving at the exterior radio frequency identification tag a pollingsignal from the external interrogator at a first time when the containeris open, the polling signal being a request for the inventoryinformation; and sending the inventory information at a second time tothe external interrogator in response to the container being closed, thesecond time being after the first time.
 17. An apparatus, comprising: anantenna configured to be disposed within an interior portion of acontainer and configured to receive an inventory-related informationassociated with an object disposed within the container; and a datastorage component configured to receive the inventory-relatedinformation received at the antenna in response to a signal and afterthe container is closed.
 18. The apparatus of claim 17, furthercomprising: a radio frequency identification tag configured to becoupled to an exterior portion of the container, the radio frequencyidentification tag configured to receive the inventory-relatedinformation from the data storage component in response to a requestfrom an external interrogator.
 19. The apparatus of claim 17, furthercomprising: a radio frequency identification tag configured to bedisposed within the interior portion of the container, the radiofrequency identification tag configured to be coupled to the antenna andthe data storage component, the inventory-related information beingtransferred from the antenna to the data storage component via the radiofrequency identification tag in response to the container being closed.20. The apparatus of claim 17, further comprising: a radio frequencyidentification tag configured to be coupled to an exterior portion ofthe container and configured to receive the inventory-relatedinformation from the data storage component, the data storage componentconfigured to be prevented from transferring the inventory indicator toan external interrogator when the container is open.